1) Field of the Invention
The present invention is concerned with the application of a dye to human hair using a one-part shampoo based formulation.
2) Description of Related Art
Certain hair dyes, namely Basic Blue 99, Basic Brown 16, Basic Brown 17, Basic Red 76, and Basic Yellow 57 have been available for use in cosmetic products since the 1970's. They were specifically designed to be used as hair colorants, and have been adapted for use in color refreshing shampoos and conditioners since their commercial availability. These products were intended to enhance previously colored hair by attaching themselves to anionic sites on the hair's surface. The dyes listed above have cationic charges on the dye molecule and are well suited for instant coloration in this fashion. They have only been used as refreshing products as the damage caused by oxidation haircoloring compositions increased the anionic sites to a degree where a small deposit of coloration can occur each time the hair is shampooed. This would then maintain a fresh colored appearance of the hair that had been treated with an oxidation haircolor. Any new re-growth of pigmented or gray hair would not be affected by the refreshing shampoo which required an additional retouch of oxidation haircolor every four to six weeks. The present invention is concerned with the coloring of gray hair that has not been subjected to a prior oxidation haircoloring process or to other chemical treatments that would increase the anionic sites on the hair's surface. It will deposit increasing amounts of color when used daily over a two to three week period. At that point the number of anionic sites are depleted and the degree of coloration will plateau. A particular advantage of the shampoo formulation of the invention is that there is no need for an additional treatment to help reduce the amount of visible gray hair. The shampoo can replace one's normal product that is used to clean head hair and will color gray hair.